No, it is a continuum, a spectrum, with individuals that do not fit into the binary.
Actually, there is.
First of all, scientists have known for decades that human brains are dimorphic (either male or female) - and now there has been great research done with AI targeting specific differences in brain structures in males and females
AI Targets Location Where Female and Male Brains Differ
And further studies and research -
support to the notion that the underlying brain anatomy in transgender people is shifted away from their biological sex towards their gender identity.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8955456/
The brain develops under the influence of not only genes, but hormones, too.